CVE-2018-12843 in Acrobat Reader
Summary
by MITRE
Adobe Acrobat and Reader versions 2018.011.20063 and earlier, 2017.011.30102 and earlier, and 2015.006.30452 and earlier have an out-of-bounds read vulnerability. Successful exploitation could lead to information disclosure.
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Analysis
by VulDB Data Team • 08/07/2024
Adobe Acrobat and Reader applications contain a critical out-of-bounds read vulnerability that affects multiple version ranges including 2018.011.20063 and earlier, 2017.011.30102 and earlier, and 2015.006.30452 and earlier. This vulnerability falls under the CWE-129 weakness category, specifically representing an out-of-bounds read condition where the software fails to properly validate array indices or buffer boundaries before accessing memory locations. The flaw occurs when processing maliciously crafted PDF documents that trigger improper bounds checking during the parsing of embedded objects or data structures within the document. When exploited, this vulnerability allows an attacker to read data from memory locations beyond the intended buffer boundaries, potentially exposing sensitive information including cryptographic keys, passwords, or other confidential data stored in adjacent memory regions. The security implications extend beyond simple information disclosure as this vulnerability can be leveraged as a stepping stone for more sophisticated attacks. According to the ATT&CK framework, this represents a technique that can be used for initial access and privilege escalation through information gathering activities. The vulnerability is particularly concerning because it can be triggered through simple document interaction without requiring user confirmation or special privileges, making it highly exploitable in phishing campaigns or social engineering attacks. The out-of-bounds read condition typically manifests when the application attempts to parse malformed or specially crafted PDF elements such as embedded fonts, images, or metadata fields that contain maliciously constructed index values or length parameters. This vulnerability is classified as a remote code execution risk because the information disclosure can provide attackers with sufficient data to craft more targeted attacks against the victim's system. The exploitation process often involves crafting a PDF document that, when opened by an affected version of Acrobat or Reader, causes the application to read beyond allocated memory boundaries and subsequently expose sensitive information from the application's memory space.
The operational impact of CVE-2018-12843 extends across enterprise environments where Adobe Acrobat and Reader are widely deployed for document processing and viewing. Organizations using these applications for business-critical document workflows face significant risk as attackers can potentially extract confidential data from memory during document processing operations. This vulnerability particularly affects industries handling sensitive information such as financial services, healthcare, legal services, and government agencies where document security is paramount. The vulnerability's exploitation requires minimal user interaction, making it particularly dangerous in targeted attack scenarios where adversaries can send malicious PDF attachments through email or other communication channels. Security teams must consider this vulnerability as part of their threat modeling activities, particularly when evaluating the risk of document-based attacks in their security posture. The vulnerability demonstrates the importance of maintaining up-to-date software versions and implementing proper document sanitization processes. Organizations should also consider deploying application whitelisting solutions and sandboxing technologies to limit the potential impact of exploitation attempts. The vulnerability's presence in multiple version lines indicates a persistent flaw in the software's memory management and input validation mechanisms, suggesting that similar issues may exist in other parts of the application's codebase. This makes the vulnerability particularly dangerous as it may indicate broader architectural weaknesses in how the application handles memory operations and data validation. The information disclosure aspect of the vulnerability can be particularly damaging when combined with other attack vectors, as the leaked memory contents may include session tokens, encryption keys, or other sensitive data that could be used to compromise additional systems or escalate privileges within the victim environment.
Mitigation strategies for CVE-2018-12843 should prioritize immediate patching of affected Adobe Acrobat and Reader installations with the latest security updates provided by Adobe. Organizations should implement a comprehensive vulnerability management program that includes regular assessment of software inventory to identify all instances of affected applications. Network-based mitigations such as PDF content filtering and sandboxing solutions can provide additional protection layers while patches are being deployed. Security teams should also consider implementing email filtering rules that block suspicious PDF attachments and establish procedures for verifying document authenticity before opening. The vulnerability's nature suggests that implementing strict input validation and memory boundary checking mechanisms should be prioritized in any defensive measures. Organizations should also consider conducting security awareness training for users to recognize potentially malicious PDF documents and avoid opening attachments from untrusted sources. Monitoring for suspicious network activity related to PDF processing and implementing intrusion detection systems that can identify exploitation attempts is recommended. The vulnerability's classification as an information disclosure risk necessitates that organizations review their data loss prevention policies and ensure that sensitive information is adequately protected even when applications are compromised. Regular security assessments should include testing for similar memory corruption vulnerabilities in other applications and systems to identify potential related weaknesses. The remediation process should also involve validating that patches have been properly applied and that no instances of vulnerable software remain in the organization's environment. Additionally, organizations should consider implementing automated patch management solutions to ensure that all systems are kept up-to-date with the latest security fixes and that vulnerabilities are addressed promptly.